View
8
Download
0
Category
Preview:
Citation preview
Geotechnical Evaluation Report
Ledford Accounting 2801 Paramount Blvd. Amarillo, TX 79109 Prepared for
Chuck Lynch Architects
Shane Nance, P.E. Principal, Business Unit Manager – Senior Engineer License Number: 81519 February 1, 2018 Project B1713164 Braun Intertec Corporation TBPE Firm Registration No. F-12228
Braun Intertec Corporation 215 South Fannin St. Amarillo, TX 79106
Phone: 806.677.0600 Web: braunintertec.com
February 1, 2018 Project B1713164 Mr. Chuck Lynch Chuck Lynch Architects 1001 SE 3rd Avenue Amarillo, TX 79102 806.374.0676 clynch@crlarchitects.com Re: Geotechnical Evaluation Ledford Accounting 2801 Paramount Blvd. Amarillo, TX 79109 Dear Mr. Lynch: We are pleased to present this Geotechnical Evaluation Report for the referenced site. Thank you for making Braun Intertec your geotechnical consultant for this project. If you have questions about this report or if there are other services that we can provide in support of our work to date please contact Shane Nance at 806.677.0600 (snance@braunintertec.com). Sincerely, BRAUN INTERTEC CORPORATION TBPE Firm Registration No. F-12228
Shane Nance, P.E. Principal, Business Unit Manager – Senior Engineer
S. Brent McNeme, P.E. Associate Principal – Client Service Manager
Table of Contents
Description Page A. Introduction ..................................................................................................................................... 1
A.1. Project Description ............................................................................................................. 1 A.2. Purpose ............................................................................................................................... 1 A.3. Scope of Services ................................................................................................................ 2
B. Results .............................................................................................................................................. 2 B.1. Geologic Overview .............................................................................................................. 2 B.2. Groundwater ....................................................................................................................... 3 B.3. Laboratory Test Results ...................................................................................................... 3
C. Recommendations ........................................................................................................................... 4 C.1. Site Grading and Subgrade Preparation ............................................................................. 4
C.1.a. Building Subgrade Preparation .............................................................................. 4 C.1.b. Excavation Oversizing ............................................................................................ 4 C.1.c. Excavated Slopes.................................................................................................... 5 C.1.d. Subgrade Proof Roll ............................................................................................... 6 C.1.e. Fill Materials and Compaction ............................................................................... 6 C.1.f. Inspections of Soils ................................................................................................ 7
C.2. Spread Footings .................................................................................................................. 8 C.3. Floor Slabs ........................................................................................................................... 8
C.3.a. Subgrade Modulus ................................................................................................. 8 C.4. Pavements .......................................................................................................................... 9
C.4.a. Design Sections ...................................................................................................... 9 C.4.b. Concrete Pavements .............................................................................................. 9 C.4.c. HMA Pavement Materials .................................................................................... 10 C.4.d. Subgrade Drainage ............................................................................................... 10 C.4.e. Performance and Maintenance ........................................................................... 10
C.5. Utilities .............................................................................................................................. 10 C.5.a. Subgrade Stabilization ......................................................................................... 10
C.6. Equipment Support ........................................................................................................... 11 C.7. Seismic Site Classification ................................................................................................. 11
D. Procedures ..................................................................................................................................... 11 D.1. Test Borings....................................................................................................................... 11 D.2. Exploration Logs ................................................................................................................ 11 D.3. Material Classification and Testing ................................................................................... 12
D.3.a. Visual and Manual Classification ......................................................................... 12 D.3.b. Laboratory Testing ............................................................................................... 12
D.4. Groundwater Measurements ........................................................................................... 12 E. Qualifications ................................................................................................................................. 12
E.1. Variations in Subsurface Conditions ................................................................................. 12 E.1.a. Material Strata ..................................................................................................... 12 E.1.b. Groundwater Levels ............................................................................................. 12
E.2. Continuity of Professional Responsibility ......................................................................... 13 E.2.a. Plan Review .......................................................................................................... 13 E.2.b. Construction Observations and Testing ............................................................... 13
E.3. Use of Report .................................................................................................................... 13 E.4. Standard of Care ............................................................................................................... 13
Appendix Soil Boring Location Sketch Log of Boring Sheets ST-1 through ST-2 Descriptive Terminology of Soil
A. Introduction
A.1. Project Description
This Geotechnical Evaluation Report addresses the design and construction of the proposed new single-
story office building and parking lot for Ledford Accounting. The site is located at 2801 Paramount
Boulevard in Amarillo, TX. Figure 1 below shows an illustration of the proposed site location.
Figure 1. Site Location
Figure provided by Google Earth.
A.2. Purpose
The purpose of our geotechnical evaluation will be to characterize the subsurface geologic conditions at this site and evaluate the impact on the design and construction of the project.
Site Location
Ledford Accounting Project B1713164 February 1, 2018 Page 2
A.3. Scope of Services
We performed our scope of services for the project in accordance with our Proposal QTB070953 to Mr.
Chuck Lynch of Chuck Lynch Architects, dated December 28, 2017 and authorized on December 29,
2017. The following list describes the geotechnical tasks completed in accordance with our authorized
scope of services.
Coordinating the staking and clearing the exploration location of underground utilities.
Chuck Lynch Architects selected and we staked the exploration locations using handheld
GPS technology. The Soil Boring Location Sketch included in the Appendix shows the
approximate locations of the borings.
Performing 2 soil borings, denoted as ST-1 and ST-2, extending both borings to a depth of 25
feet below existing grade.
Performing semi-continuous sampling to a depth of 10 feet, and at 5-foot intervals at
greater depths in general accordance with American Society for Testing and Materials
(ASTM) D1586.
Performing laboratory testing on select samples to aid in soil classification and engineering
analysis.
Perform engineering analysis including estimation of potential vertical rises and foundation
bearing capacity analysis.
Preparing this report containing the findings of our field exploration, laboratory testing and
engineering recommendations.
B. Results
B.1. Geologic Overview
Based upon our review of available geologic resources, the site is underlain by the Playa Deposits
Formation (Qp) and is in close proximity to the Blackwater Draw Formation (Qbd). The Playa Deposits
Formation consists of sandy clay and silt, gray color in shallow depressions, usually covered by thin
deposits of recent sediment; weathers light gray.
Ledford Accounting Project B1713164 February 1, 2018 Page 3
Figure 2. Geologic Map
(http://txpub.usgs.gov/DSS/texasgeology)
We based the geologic origins used in this report on the soil types and available common knowledge of
the geological history of the site. We did not perform a detailed investigation of the geologic history for
the site.
B.2. Groundwater
Groundwater was not observed while advancing the borings. It appears that groundwater is below the
depths explored. Project planning should anticipate seasonal and annual fluctuations of groundwater.
B.3. Laboratory Test Results
The boring logs show the results of Moisture Content (ASTM D2216), Atterberg Limits (ASTM D4318),
and Percent Finer than No. 200 sieve (ASTM D1140) tests we performed, next to the tested sample
depth. We performed the tests in general accordance with ASTM procedures. The Appendix contains the
results of these tests.
SITE
Playa Deposits Formation (Qp)
http://txpub.usgs.gov/DSS/texasgeology
Ledford Accounting Project B1713164 February 1, 2018 Page 4
The moisture content of the tested samples varied from approximately 12 to 30 percent. Liquid limits
determined for the soils ranged from 26 to 60; plasticity index values ranged from 8 to 35. A highly
expansive clay soil was found in the upper 18.5 feet and a less expansive sandy material was
encountered below 18.5 feet. Atterberg limit testing is necessary to confirm the classification of the
subsoils encountered at various depths in the borings and provide an indication of the relative strength,
the potential for volumetric expansion and contraction with respect to changes in moisture content, and
compressibility of the subsoils. These results of Atterberg Limit testing within the scope of this project
indicate that the soils tested have a low to high expansive potential.
C. Recommendations
The Potential Vertical Rise (PVR) was estimated for the site to be on the order of 2 to 3 inches using
Texas Department of Transportation method (Test Procedure TEX-124-E) in a dry condition. Based on
information provided, a shallow foundation system is believed to be a practical means of support. Refer
to the following text for site grading and subgrade preparations, and shallow foundation design
recommendations.
C.1. Site Grading and Subgrade Preparation
C.1.a. Building Subgrade Preparation
We recommend removing vegetation, loose topsoil, construction debris and other deleterious material
from the building pad area. To achieve an estimated PVR of near 1 inch, the existing soils, beneath the
proposed building footprint, should be either 1) moisture-conditioned to a depth of 7 feet below the
bottom of the footings, or 2) removed and replaced with select fill to a depth of 3 feet below the bottom
of the footings; assuming the footings are situated at least 2 feet below the existing ground surface.
After the existing soils have been overexcavated to the require depth, we recommend proof-rolling the
subgrade soil as described in section C.1.d. Once the proof roll is complete, the subgrade soils should be
scarified to a minimum depth of 8 inches, and recompacted to 95% Standard Proctor Density (ASTM
D698), at 0% to +4% of optimum moisture. The removed native soils may be moisture conditioned and
replaced at 93-98% Standard Proctor Density (ASTM D698) and at a minimum of +5% of optimum
moisture or select fill may be place as outlined in section C.1.e
C.1.b. Excavation Oversizing
When removing materials below structures, we recommend the excavation extend outward and
downward at a slope of 1H:1V (horizontal:vertical) or flatter. See Figure 3 for an illustration of
excavation oversizing.
Ledford Accounting Project B1713164 February 1, 2018 Page 5
Figure 3. Generalized Illustration of Oversizing
C.1.c. Excavated Slopes
Based on the borings, we anticipate on-site soils in excavations will consist of clay. These soils are
typically considered Type B Soil under OSHA (Occupational Safety and Health Administration) guidelines.
OSHA guidelines indicate unsupported excavations in Type B soils should have a gradient no steeper
than 1H:1V (45°). Slopes constructed in this manner may still exhibit surface sloughing. OSHA requires
an engineer to evaluate slopes or excavations over 20 feet in depth.
An OSHA-approved qualified person should review the soil classification in the field. Excavations must
comply with the requirements of OSHA 29 CFR, Part 1926, Subpart P, “Excavations and Trenches”. This
document states excavation safety is the responsibility of the contractor. The project specifications
should reference these OSHA requirements.
1. Select fill as defined in C.1.e or moisture conditioned soil
2. Excavation oversizing minimum of 1 to 1 (horizontal to vertical) slope or flatter
3. Backfill as required to meet pavement support or landscaping requirements as defined in C.1.e
4. Backslope to OSHA requirements
Ledford Accounting Project B1713164 February 1, 2018 Page 6
C.1.d. Subgrade Proof Roll
After preparing the subgrade as described above and prior to the placement of moisture conditioned
soil or fill material, we recommend proof rolling the subgrade soils in accordance with Texas
Department of Transportation (TxDOT) Standard Specification Item 216. We also recommend having a
geotechnical representative observe the proof roll. Areas that fail the proof roll likely indicate soft or
weak areas that will require additional soil correction work to support the structures.
The contractor should correct areas that display yielding or rutting. Possible options for subgrade
correction include moisture conditioning and recompaction, excavation and replacement with soil or
crushed aggregate, chemical stabilization and/or geotextiles. We recommend performing a second
proof roll after the moisture conditioned soil or fill material are in place, and prior to constructing the
foundations, or prior to placing asphalt or concrete pavement.
C.1.e. Fill Materials and Compaction
Table 1 below contains our recommendations for fill materials.
Table 1. Fill Materials
Locations To Be Used
Fill Classification
Possible Soil Type Descriptions Gradation
Additional Requirements
Below Structures and Pavement
Select fill SC, CL 1. 100% passing 3-inch sieve 2. 65% maximum passing
No. 200 sieve
1. Liquid Limit
Ledford Accounting Project B1713164 February 1, 2018 Page 7
Table 2. Compaction Recommendations Summary
Reference
Recommended Compaction, percent
(ASTM D698 – Standard Proctor) Moisture Content Variance from
Optimum, percentage points
Moisture conditioned soils below structures, pavement and
oversizing zone 93-98 +5 (minimum)
Select fill soils below structures, pavement and oversizing zones
95 -1 to +3
Below landscaped surfaces 90 -1 to +3
We recommend performing density tests in fill to evaluate if the contractors are effectively compacting
the soil and meeting project requirements.
C.1.f. Inspections of Soils
We recommend including the site grading and placement of soil within the building pad under the
direction of a licensed Geotechnical Engineer. Inspection requires observation of soil conditions below
fill or footings, evaluations to determine if excavations extend to the anticipated soils, and if fill
materials meet requirements for type of fill and compaction condition of fill. A licensed geotechnical
engineer should direct the inspections of site grading and fill placement. The purpose of these
inspections is to evaluate whether the work is in accordance with the approved Geotechnical Report for
the project. Special inspections should include evaluation of the subgrade, observing preparation of the
subgrade (surface compaction or dewatering, excavation oversizing, placement procedures and
materials used for fill, etc.) and compaction testing of the fill.
Ledford Accounting Project B1713164 February 1, 2018 Page 8
C.2. Spread Footings
Table 3 contains our recommended parameters for shallow foundation design.
Table 3. Recommended Spread Footing Design Parameters
Item Description
Maximum net allowable bearing pressure (psf) Pad footings (moisture conditioned soil)
Perimeter strip footings (moisture conditioned soil)
Pad footings (select fill) Perimeter strip footings (select fill)
1,500 1,200
2,000 1,700
Minimum factor of safety for bearing capacity failure 3.0
Minimum width (inches) Pad footings
Perimeter strip footings
24 16
Minimum embedment below final exterior grade for structures (inches)
24
Total estimated settlement (inches) Less than 2 inches
Differential settlement Typically about 2/3 of total settlement*
* Actual differential settlement amounts will depend on final loads and foundation layout.
Spread footings can be situated on moisture conditioned soil/select fill with a minimum embedment
depth as recommended in the table above. Building subgrade should be appropriately prepared in
accordance with Section C.1.a.
For moisture conditioned soil, the recommended allowable passive resistance is 150 psf/ft (triangular
earth pressure distribution) and an allowable coefficient of friction equal to 0.27 is recommended for
evaluating sliding resistance. For select fill, the recommended allowable passive resistance is 175 psf/ft
(triangular earth pressure distribution) and an allowable coefficient of friction equal to 0.34 is
recommended for evaluating sliding resistance.
C.3. Floor Slabs
C.3.a. Subgrade Modulus
The anticipated floor subgrade is select fill or moisture conditioned clay soil. We recommend using a
modulus of subgrade reaction, k, of 125 (select fill) or 100 (moisture conditioned clay soil) pounds per
square inch per inch (pci) of deflection to design the slabs. If the slab design requires placing 6 inches of
Ledford Accounting Project B1713164 February 1, 2018 Page 9
compacted crushed aggregate base immediately below the slab, the slab design may increase the k-
value by 50 pci. In addition to improving the modulus of subgrade reaction, an aggregate base facilitates
construction activities and is less weather sensitive.
C.4. Pavements
C.4.a. Design Sections
Our scope of services for this project did not included laboratory tests on subgrade soils to determine a
CBR value for pavement design. Based on our experience with similar soils anticipated at the pavement
subgrade elevation, we recommend a pavement design CBR value of 4. Table 4 provides recommended
pavement sections, based on the soils support and traffic loads.
Table 4. Recommended Pavement Sections (Light Duty)
Pavement Type Pavement Section
Portland Cement Concrete 5.0" Portland Cement Concrete 8.0" Density-Controlled Native Soil (lime treated) or Select Fill
Full Depth HMAC
2.0” Dense HMAC with 1/2-inch nominal maximum size aggregate or equivalent – Surface
3.0” Dense HMAC with 3/4-inch nominal maximum size aggregate or equivalent – Base
8.0” Density Controlled Native Soil (lime treated) or Select Fill
HMAC Over Crushed Aggregate Base
2.0” Dense HMAC with 1/2-inch nominal maximum size aggregate or equivalent – Surface
6.0” Aggregate Base Course (flexible) 8.0” Density Controlled Native Soil (lime treated) or Select Fill
NOTE: Materials shall meet general requirements of the local governing bodies, TxDOT Standard Specifications for Construction and Maintenance of Highways, Streets, & Bridges, and specific requirements listed herein.
For fire lanes and dumpster aprons, it is recommended to place at least 7 inches of concrete pavement
over 8 inches of density controlled native soil (lime treated) or select fill. Based on past experience, 6%
lime should be used to treat the native soils – the amount of lime needed to treat the soil should be
confirmed prior to construction.
C.4.b. Concrete Pavements
We recommend placing select fill or lime treating the existing soils below the pavement to provide a
suitable subgrade for concrete placement, reduce faulting and help dissipate loads. Appropriate mix
designs, panel sizing, jointing, doweling and edge reinforcement are critical to performance of rigid
pavements. We recommend you contact your civil engineer to determine the final design or consult
with us for guidance on these items.
Ledford Accounting Project B1713164 February 1, 2018 Page 10
C.4.c. HMA Pavement Materials
Appropriate mix designs are critical to the performance of flexible pavements. The Braun pavement
group can provide recommendations for pavement material selection during final pavement design.
C.4.d. Subgrade Drainage
We recommend installing perforated drainpipes throughout pavement areas at low points, around catch
basins, and behind curbs in landscaped areas. We also recommend installing drainpipes along pavement
and exterior slab edges where exterior grades promote drainage toward those edge areas. The
contractor should place drainpipes in small trenches, extended at least 8 inches below the aggregate
base material.
C.4.e. Performance and Maintenance
We based the above pavement designs on a performance life based on typical traffic counts for similar
projects Braun has conducted. This performance life assumes routine maintenance, such as seal coating
and crack sealing. The actual pavement life will vary depending on variations in weather, traffic
conditions and maintenance.
Many conditions affect the overall performance of the exterior slabs and pavements. Some of these
conditions include the environment, loading conditions and the level of ongoing maintenance. With
regard to asphalt pavements in particular, it is common to have thermal cracking develop within the first
few years of placement, and continue throughout the life of the pavement. We recommend developing
a regular maintenance plan for filling cracks in exterior slabs and pavements to lessen the potential
impacts for warm weather distress due to wetting and softening of the subgrade.
C.5. Utilities
C.5.a. Subgrade Stabilization
Earthwork activities associated with utility installations located inside the building footprint should
adhere to the recommendations in Section C.1.
For exterior utilities, we anticipate the soils at typical invert elevations will be suitable for utility support.
However, if construction encounters unfavorable conditions, the unsuitable soils may require some
additional subcutting and replacement with sand or crushed rock to prepare a proper subgrade for pipe
support. Project design and construction should not place utilities within the 1H:1V oversizing of
foundations.
Ledford Accounting Project B1713164 February 1, 2018 Page 11
C.6. Equipment Support
The recommendations included in the report may not be applicable to equipment used for the
construction and maintenance of this project. We recommend evaluating subgrade conditions in areas
of shoring, scaffolding, cranes, pumps, lifts and other construction equipment prior to mobilization to
determine if the exposed materials are suitable for equipment support, or require some form of
subgrade improvement. We also recommend project planning consider the effect that loads applied by
such equipment may have on structures they bear on or surcharge – including pavements, buried
utilities, below-grade walls, etc. We can assist you in this evaluation.
C.7. Seismic Site Classification
Due to project budget limitation, we did not perform a 100-foot deep boring recommended in the
International Building Code (IBC) for seismic site classification. We conservatively assumed the
overburden soil consistency continues below the bottom of the borings. Based on the soil boring data
and pertinent reference materials, this site meets the criteria for Site Class E as defined in Table
1613.5.2 of Chapter 16 of the 2015 IBC.
D. Procedures
D.1. Test Borings
We drilled the borings with a truck-mounted auger drill. We performed the borings in general
accordance with ASTM D1586 taking samples semi-continuously to a depth of 10 feet and then 5-foot
intervals thereafter. The boring logs show the actual sample intervals and corresponding depths.
D.2. Exploration Logs
The Appendix includes Log of Boring sheets for our test borings. The logs identify and describe the
penetrated geologic materials, and present the results of penetration resistance and other in-situ tests
performed. The logs also present the results of laboratory tests performed on test samples, and
groundwater measurements.
We inferred strata boundaries from changes in the test samples and the auger cuttings. Because we did
not perform continuous sampling, the strata boundary depths are only approximate. The boundary
depths likely vary away from the boring locations, and the boundaries themselves may occur as gradual
rather than abrupt transitions.
Ledford Accounting Project B1713164 February 1, 2018 Page 12
D.3. Material Classification and Testing
D.3.a. Visual and Manual Classification
We visually and manually classified the geologic materials encountered in accordance with ASTM D2488.
The Appendix includes a chart explaining the classification system.
D.3.b. Laboratory Testing
The exploration logs in the Appendix note most of the results of the laboratory tests performed on
geologic material samples. The remaining laboratory test results follow the exploration logs. We
performed the tests in general accordance with ASTM or AASHTO procedures.
D.4. Groundwater Measurements
The drillers checked for groundwater while advancing the test borings, and again after auger
withdrawal. We then filled the boreholes as noted on the boring logs.
E. Qualifications
E.1. Variations in Subsurface Conditions
E.1.a. Material Strata
We developed our evaluation, analyses and recommendations from a limited amount of site and
subsurface information. It is not standard engineering practice to retrieve material samples from
exploration locations continuously with depth. Therefore, we must infer strata boundaries and
thicknesses to some extent. Strata boundaries may also be gradual transitions, and project planning
should expect the strata to vary in depth, elevation and thickness, away from the exploration locations.
Variations in subsurface conditions present between exploration locations may not be revealed until
performing additional exploration work, or starting construction. If future activity for this project reveals
any such variations, you should notify us so that we may reevaluate our recommendations. Such
variations could increase construction costs, and we recommend including a contingency to
accommodate them.
E.1.b. Groundwater Levels
We made groundwater measurements under the conditions reported herein and shown on the
exploration logs, and interpreted in the text of this report. Note that the observation periods were
Ledford Accounting Project B1713164 February 1, 2018 Page 13
relatively short, and project planning can expect groundwater levels to fluctuate in response to rainfall,
flooding, irrigation, seasonal freezing and thawing, surface drainage modifications and other seasonal
and annual factors.
E.2. Continuity of Professional Responsibility
E.2.a. Plan Review
We based this report on a limited amount of information, and we made a number of assumptions to
help us develop our recommendations. We should be retained to review the geotechnical aspects of the
designs and specifications. This review will allow us to evaluate whether we anticipated the design
correctly, if any design changes affect the validity of our recommendations, and if the design and
specifications correctly interpret and implement our recommendations.
E.2.b. Construction Observations and Testing
We recommend retaining us to perform the required observations and testing during construction as
part of the ongoing geotechnical evaluation. This will allow us to correlate the subsurface conditions
exposed during construction with those encountered by the borings and provide professional continuity
from the design phase to the construction phase. If we do not perform observations and testing during
construction, it becomes the responsibility of others to validate the assumption made during the
preparation of this report and to accept the construction-related geotechnical engineer-of-record
responsibilities.
E.3. Use of Report
This report is for the exclusive use of the addressed parties. Without written approval, we assume no
responsibility to other parties regarding this report. Our evaluation, analyses and recommendations may
not be appropriate for other parties or projects.
E.4. Standard of Care
In performing its services, Braun Intertec used that degree of care and skill ordinarily exercised under
similar circumstances by reputable members of its profession currently practicing in the same locality.
No warranty, express or implied, is made.
Appendix
PLAN OF BORINGS Ledford Accounting
2801 Paramount Boulevard Amarillo, TX 79109
JG 1/26/2018
SN 1/26/2018
B1713164
1 No Scale 1 1
60
48
27
21
33
27
7
7
9
8
7
7
13
27
30
28
25
29
21
16
97
96
CH
CH
CL
CH
SC
SANDY FAT CLAY, light gray, medium stiff
FAT CLAY, dark gray, medium stiff
- stiff at 5.5 ft
LEAN CLAY, gray, medium stiff
FAT CLAY, olive yellow, medium stiff
CLAYEY SAND, gray, loose
- medium dense below 23.5 ft
END OF BORING.
Boring immediately backfilled.
Elevations not provided. A datum of 100 wasset as the existing ground surface at eachboring
96.5
91.5
86.5
81.5
75.0
3.5
8.5
13.5
18.5
25.0
B. Faulkner 1/4/18 1" = 4'
MC%
DDpcf
LL PL PIWLBPFTests
orNotes
DATE: SCALE:DRILLER:
L O G O F B O R I N GS
ee D
escr
iptiv
e T
erm
inol
ogy
shee
t for
exp
lana
tion
of a
bbre
viat
ions
)
LOCATION: See Attached Sketch
ST-1
METHOD:
WL
Description of MaterialsP200
%(Soil-ASTM D2488 or D2487,
Rock-USACE EM1110-1-2908)
BORING:
Braun Intertec ST-1 page 1 of 1
See Attached Sketch
Braun Project B1713164GEOTECHNICAL EVALUATIONLedford Accounting2801 Paramount Blvd.Amarillo, TX
B1713164
Symbol
Elev.feet100.0 0.0
Depthfeet
58
57
26
23
28
18
35
29
8
6
6
9
8
9
8
14
24
30
29
26
27
16
12
70
99
42
CH
CH
CL
CH
SC
SANDY FAT CLAY, gray, medium stiff
FAT CLAY, dark gray, medium stiff
- stiff at 5.5 ft
LEAN CLAY, gray, medium stiff
FAT CLAY, olive yellow, stiff
CLAYEY SAND, gray, loose
- medium dense below 23.5 ft
END OF BORING.
Boring immediately backfilled.
Elevations not provided. A datum of 100 wasset as the existing ground surface at eachboring
96.5
91.5
86.5
81.5
75.0
3.5
8.5
13.5
18.5
25.0
B. Faulkner 1/4/18 1" = 4'
MC%
DDpcf
LL PL PIWLBPFTests
orNotes
DATE: SCALE:DRILLER:
L O G O F B O R I N GS
ee D
escr
iptiv
e T
erm
inol
ogy
shee
t for
exp
lana
tion
of a
bbre
viat
ions
)
LOCATION: See Attached Sketch
ST-2
METHOD:
WL
Description of MaterialsP200
%(Soil-ASTM D2488 or D2487,
Rock-USACE EM1110-1-2908)
BORING:
Braun Intertec ST-2 page 1 of 1
See Attached Sketch
Braun Project B1713164GEOTECHNICAL EVALUATIONLedford Accounting2801 Paramount Blvd.Amarillo, TX
B1713164
Symbol
Elev.feet100.0 0.0
Depthfeet
Descriptive Terminology of SoilBased on Standards ASTM D 2487-11/2488-09a
(Unified Soil Classification System)
Group
Symbol Group NameB
Cu ≥ 4 and 1 ≤ Cc ≤ 3D GW Well-graded gravel
E
Cu < 4 and/or (Cc < 1 or Cc > 3)D GP Poorly graded gravel
E
Fines classify as ML or MH GM Silty gravelE F G
Fines Classify as CL or CH GC Clayey gravelE F G
Cu ≥ 6 and 1 ≤ Cc ≤ 3D SW Well-graded sand
I
Cu < 6 and/or (Cc < 1 or Cc > 3)D SP Poorly graded sand
I
Fines classify as ML or MH SM Silty sandF G I
Fines classify as CL or CH SC Clayey sandF G I
CL Lean clayK L M
PI < 4 or plots below "A" lineJ ML SiltK L M
Organic OL
CH Fat clayK L M
MH Elastic siltK L M
Organic OH
PT Peat Highly Organic Soils
Silts and Clays
(Liquid limit less than
50)
Silts and Clays
(Liquid limit 50 or
more)
Primarily organic matter, dark in color, and organic odor
Inorganic
Inorganic
PI > 7 and plots on or above "A" lineJ
PI plots on or above "A" line
PI plots below "A" line
Criteria for Assigning Group Symbols and
Group Names Using Laboratory TestsA
Soil Classification
Co
arse
-gra
ine
d S
oils
(m
ore
th
an 5
0%
ret
ain
ed o
n
No
. 20
0 s
ieve
)
Fin
e-g
rain
ed
So
ils
(5
0%
or
mo
re p
asse
s th
e
No
. 20
0 s
ieve
)
Sands
(50% or more coarse
fraction passes No. 4
sieve)
Clean Gravels
(Less than 5% finesC)
Gravels with Fines
(More than 12% finesC)
Clean Sands
(Less than 5% finesH)
Sands with Fines
(More than 12% finesH)
Gravels
(More than 50% of
coarse fraction
retained on No. 4
sieve)
Liquid Limit − oven dried
Liquid Limit − not dried 4 tsf
Drilling Notes:BPF: Numbers indicate blows per foot recorded in standard penetration test, also known as “N” value. The sampler was set 6 inches into undisturbed soil below the hollow-stem auger. Driving resistances were then counted for second and third 6-inch increments, and added to get BPF.
Partial Penetration: If the sampler cannot be driven the full 12 inches beyond the initial 6-inch set, the number of blows for that partial penetration is shown as "No./X" (i.e., 50/2"). If the sampler cannot be advanced beyond the initial 6-inch set, the depth of penetration will be recorded in the Notes column as "No. to set X" (i.e., 50 to set 4").
WH: WH indicates the sampler penetrated soil under weight of hammer and rods alone; driving not required.
WR: WR indicates the sampler penetrated soil under weight of rods alone; hammer weight and driving not required.
WL: WL indicates the water level measured by the drillers either while drilling or following drilling.
Moisture Content:Dry: Absence of moisture, dusty, dry to the touch.Moist: Damp but no visible water.Wet: Visible free water, usually soil is below water table.
1/2018
Recommended